A BIOMETRICAL GENOME SEARCH IN RATS REVEALS THE MULTIGENIC BASIS OF BLOOD-PRESSURE VARIATION

A genome-wide search For multiple loci influencing salt-loaded systoli c blood pressure (NaSBP) variation among 188 F-2 progeny from a cross between the Brown-Norway and spontaneously hypertensive rat strains wa s pursued in an effort to gain insight into the polygenic basis of blo od pressure re,oulation. The results suggest that loci within five to six genomic regions collectively explain similar to 43% of the total N aSBP variation exhibited among the 188 F-2 progeny. Many of these loci are in regions that previous studies have not implicated in blood pre ssure regulation. Ultimately, however, this study not only sheds light on the multigenic basis of blood pressure but provides further eviden ce that the identification of the genetic determinants of polygenic tr aits in mammals is possible with modern biometrical and molecular gene tic tools in controlled settings (i.e., breeding paradigm and model or ganism).